Assessing Anosognosia in Apraxia of Common Tool-Use With the VATA-NAT

Abstract

In neurological patients, a lack of insight into their impairments can lead to possibly dangerous situations and non-compliance in rehabilitation therapy with worse rehabilitation outcomes as a result. This so called anosognosia is a multifaceted syndrome that can occur after brain damage affecting different neurological or cognitive functions. To our knowledge no study has investigated anosognosia for apraxia of common tool-use (CTU) so far. CTU-apraxia is a disorder frequently occurring after stroke that affects the use of familiar objects. Here, we introduce a new questionnaire to diagnose anosognosia for CTU-apraxia, the Visual Analogue Test assessing Anosognosia for Naturalistic Action Tasks (VATA-NAT). This assessment is adapted from a series of VATA-questionnaires that evaluate insight into motor (VATA-M) or language (VATA-L) impairment and take known challenges such as aphasia into account. Fifty one subacute stroke patients with left (LBD) or right (RBD) brain damage were investigated including patients with and without CTU-apraxia. Patients were assessed with the VATA-L, -M and -NAT before and after applying a diagnostics session for each function. Interrater reliability, composite reliability as well as convergent and divergent validity were evaluated for the VATA-NAT. Seven percent of the LBD patients with CTU-apraxia demonstrated anosognosia. After tool-use diagnostics this number increased to 20 percent. For the VATA-NAT, psychometric data revealed high interrater-reliability (τ ≥ 0.828), composite reliability (CR ≥ 0.809) and convergent validity (τ = −0.626). When assessing patients with severe aphasia, the possible influence of language comprehension difficulties needs to be taken into account for interpretation. Overall, close monitoring of anosognosia over the course of rehabilitation is recommended. With the VATA-NAT we hereby provide a novel assessment for anosognosia in patients with CTU-apraxia. For diagnosing anosognosia we recommend to combine this new tool with the existing VATA-M and -L subtests, particularly in patients who demonstrate severe functional deficits.

Anosognosia for limb and bucco‐facial apraxia as inferred from the recognition of gestural errors

“…In that study, the BFA participants (but not the non‐apraxic left damaged or RBD participants) failed to report their errors during action execution, judging incorrect actions as correct. More recently, a tool for assessing AA has been devised (Buchmann, Jung, Liepert, & Randerath, 2018) and another study has investigated awareness for LA by means of a comparison between the judgements of an examiner and the participants with regard to their proficiency in action execution (Kusch et al , 2018). In that study, the independency between anosognosia for apraxia and for aphasia was reported.…”

Syndromes of limb apraxia: Developmental and acquired disorders of skilled movements.

“…Preliminary studies developed and applied questionnaires assessing the ability to produce gestures (Kusch et al, 2018) or to plan and perform naturalistic single and multistep actions (Buchmann et al, 2018). Among patients with limb apraxia, unawareness for their symptoms has been reported, with incidence rates ranging from 20% to 50% (Buchmann et al, 2018;Kusch et al, 2018). The example in Figure 8.5 shows items of the Visual Analogue Test Assessing Anosognosia for Naturalistic Action Tasks (VATA-NAT).…”

A combined therapy for limb apraxia and related anosognosia

“…Patients were selected based upon their performance in the Diagnostic Instrument for Limb Apraxia -Short Version Buchmann et al, 2019;Randerath, Buchmann, Liepert, & Büsching, 2017) and in the Visual-Analogue Test assessing Anosognosia for Naturalistic Action Tasks (VATA-NAT; Buchmann et al, 2018). To be included in this study, patients had to Figure 2.…”

“…Also, none of the trainings included supported self-evaluation as an approach to address a lack of insight into the impairment (anosognosia) of solving naturalistic actions, despite the fact that anosognosia has been reported to potentially co-occur with limb apraxia (Buchmann, Jung, Liepert, & Randerath, 2018;Kusch et al, 2018) and that the performance of apraxic patients could benefit when monitoring their errors (Morady & Humphreys, 2009). Anosognosia should be taken into account for therapy approaches.…”